. Fresh-water biology. Freshwater biology. BLUE-GREEN ALGAE 113. 62 (61, 63) Sheaths thin; branches commonly unilateral. Hapalosiphon Nageli. Filaments free-floating amongst other algae or subaerial. Branches long and flexuose, slightly attenuated, generally narrower than the main axis and borne imilaterally. Primary axis consisting of a single row, rarely of 2 to 3 rows of cells, enclosed in a strong sheath of uniform thickness. Spores and heterocysts intercalary. Among water weeds, in hot springs, etc. Fig. 63. Eapalosiphon hibernicus W. and G. S. West. X 440. (After West.) 63 (61, 62) Sheat
. Fresh-water biology. Freshwater biology. BLUE-GREEN ALGAE 113. 62 (61, 63) Sheaths thin; branches commonly unilateral. Hapalosiphon Nageli. Filaments free-floating amongst other algae or subaerial. Branches long and flexuose, slightly attenuated, generally narrower than the main axis and borne imilaterally. Primary axis consisting of a single row, rarely of 2 to 3 rows of cells, enclosed in a strong sheath of uniform thickness. Spores and heterocysts intercalary. Among water weeds, in hot springs, etc. Fig. 63. Eapalosiphon hibernicus W. and G. S. West. X 440. (After West.) 63 (61, 62) Sheaths thick; fused to form an irregular gelatinous mass. Nostochopsis Wood. Forming rounded, Nostoc-like masses, attached to water plants. Filaments composed of but one cell- row; profusely branched. Fig. 64. Nostochopsis lobata Wood. X 33°. (After Bornet.) a2S£S3Ea2a3K3S3S23 64 (26) Filaments conspicuously attenuated towards one or both extrem- ities, which are generally piliferous. Suborder Trichophoreae 65 Filaments sheathed, simple or branched, attenuated from the base to the apex, which is piliferous; heterocysts generally basal, rarely absent. Family Rivulariaceae . 65 65 (68) Filaments free or forming penicillate tufts or soft velvety expan- sions ... . .66 66 (67) Branches, when present, distinct and free. . Calothrix Agardh. Filaments simple or slightly branched, single in a thick sheath; hetero- cysts basal or intercalary or, in a few species, absent. Forming tufts or soft velvety expan- sions on wet or sub- merged rocks. Fig. 65. Calothrix thermalis Hansgirg. X46s. (Origi- nal.) 67 (66) Branches several (2 to 6) within a common sheath. Dichothrix Zanardini. Filaments more or less di- chotomously branched; hetero- cysts basal or intercalary. On wet rocks, etc. Fig. 66. Dichothrix inlerrupla W. and G. S. West. X 420 (After West.) 68 (65) Filaments forming a hemispherical or globular mass, closely united by mucus. go. Please note that these images are extracted from scan
Size: 1854px × 1348px
Photo credit: © Central Historic Books / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1910, booksubjectfreshwa, bookyear1918
